When to fish, and when to cut bait...or wait, is there another option?

So, you're in a high-tech start-up, and the technology doesn't seem to be performing as you expected or the product development is hopelessly behind schedule.  What do you do?  If you're part of the founding team, or at least one of the decision-makers, when do you decide that it isn't going to work and close up shop?  When the money runs out?  Key to this thought process is to do an assessment of just exactly what intellectual property the company does have, even if it turns out that the technology has no legs.  I mention intellectual property not just in the patent sense, but also in a most general sense:  just what does the company have that is of value?  Does it have really sharp people that can recast the technology or its intellectual property into another market?  Has the company developed expertise in its original market such that even though the technology doesn't work, it knows the market and customers so well, that it can use other technology to build a product that will sell into this market?  Find out what your company has or does best, and build on that expertise to reinvent yourself.